Jordan Bowery (centre) is congratulated after scoring the winner on his Oxford United debut at Fratton Park

Jordan Bowery scored on his debut as Oxford beat fellow League Two promotion chasers Portsmouth at Fratton Park.

Bowery came off the bench to score the winner after the visitors had seen a second-half penalty saved.

Ryan Fulton twice denied Liam Sercombe from the spot after fouling Danny Hylton in the box.

Adam McGurk missed the chance to equalise late on for Portsmouth as he could only direct his close-range header straight at Sam Slocombe.

Four points and two places separated the two promotion contenders before kick-off, but both were struggling for consistency.

A goalless first half saw Portsmouth striker Marc McNulty's shot cleared off the line by Oxford captain Jake Wright, while Sercombe flashed a half-volley just wide of the post for the visitors.

Sercombe then saw his penalty saved after the break by debutant goalkeeper Fulton, who got back on his feet to block the midfielder's rebound.

Fulton, signed on a youth loan until the end of the season from Liverpool on Friday, was perhaps fortunate to still be on the pitch when he raced off his line and brought Hylton down.

But Pompey failed to capitalise on that good fortune and former Aston Villa striker Bowery, signed on a contract until the end of the season after being released by Rotherham, eventually made them pay.

His low right-foot shot found the bottom left-hand corner after Wright's long ball over the top found him in space on the edge of the box.

Portsmouth manager Paul Cook told BBC Radio Solent:

Media playback is not supported on this device

Cook on Portsmouth v Oxford

"In the first half Oxford were very strong and caused us no end of problems.

"We stuttered today. For as strong as we looked on Tuesday night (in the FA Cup against Ipswich), it was probably as weak as we've looked today.

"That's football, I've been down this game long enough to know what makes you good can also make you weak."

Oxford United manager Michael Appleton told BBC Radio Oxford:

"I thought the penalty would give us a massive lift and it certainly gave our supporters a lift.

"Portsmouth got into the game a bit after the save and we then had to ride a bit of pressure. But we also created a couple of opportunities for ourselves.

"It was a fantastic finish from Jordan Bowery. He only got to the club on Friday and hasn't played a competitive game since the end of November.

"I think you saw glimpses today of what he'll give us once we get him fully fit and what he can produce."